Non-aqueous process for reacting sultones with cellulosic materials and the product produced

ABSTRACT

Cellulose is converted into sodium cellulosate by reaction of the preswollen cellulose with sodium alkoxide and then washed with tertiary butanol prior to reaction with hydrocarbon sultone in tertiary butanol. More sulfur is added by this procedure than when water is present. The sultone solution is not contaminated by base and may be used repeatedly. This reuse of reactants reduces costs and diminishes pollution. The resultant products have active acidic sites, thus making them suitable intermediates for other reactions.

United States Patent [191 Ward et al.

[111' 3,854,868 [451 Dec. 17, 1974 NON-AQUEOUS PROCESS FOR REACTINGSULTONES WITH CELLULOSIC MATERIALS AND THE PRODUCT PRODUCED [75]Inventors: Truman L. Ward; RuthR. Benerito,

' both of New Orleans; Ralph J.

Berni, Metairie, all of La.

[73] Assignee: The United States of America as represented by theSecretary of Agriculture, Washington, DC.

22 Filed: Nov. 15, 1972 21 Appl. No: 396,770

[52] U.S. Cl. 8/116 R, 8/130.1 [51] Int. Cl..... D06m l/00 [58] Field ofSearch... ..-8/1-16 R, 130.1

[56] I References Cited 5 'UNITED STATES PATENTS 3.492.316 1/1970Adamsetal. v; ..8/l16R 3,506,390 4/1970 Naps 8/116 R 3,517,068 6/1970Perrino 8/1 16 R 3,698,857 10/1972 Vigo et a1. 3/116 R 3,748,364 7/1973Tesoro 8/116 R Primary ExaminerStephen J. Lechert, Jr.

[5 7 ABSTRACT Cellulose is Converted into sodium cellulosate by reac- I10 Claims N0 Drawings I NON-AQUEOUS PROCESS FOR REACTING SULTONES WITHCELLULOSIC MATERIALS AND THE PRODUCT PRODUCED A non-exclusive,irrevocable, royalty-free license in the invention herein described,throughout the world for all purposes of the United States Government,with the power to grant sublicenses for such purposes, is hereby grantedto the Government of the United State of America.

This invention relates to non-aqueous reactions of cellulose withhydrocarbon sultones. More specifically,

this invention relates to reaction of celluloses by known methods toprepare the sodium cellulosate which in turn is reacted with a selectedsultone in the absence of water and without the assistance of catalysts.The resultant sultone-celluloses are useful as ion-exchange agents orwhere active acidic sites are required for further reactions of thecellulosic materials.

The main object of this invention is to provide a completely non-aqueousprocess for reacting cellulose with certain hydrocarbon sultones such as1,3-propane sultone.

Another object of this invention is to provide a process by which thesultone solution is kept free of base so that it can be reusedrepeatedly.

a third objects of this invention is to provide a product which containsmore sulfur than that which is obtained by an aqueous process whereinsodium hydroxide would be used.

In the prior art US. Pat. No. 3,506,390 discloses treatment of cottonwith aqueous sodium hydroxide and further reacted in aqueous solutionwith propane sultone. The most sulfur added to the cotton by saidtreatment was 2.12%. This was obtained by the use of 25% concentrationof sultone, a rather long reaction time (75 minutes), and an elevatedtemperature of 75C.

A water soluble adduct was reported by J. H. Helberger, et al., inJustus Liebigs Annalen Der Chemie, 565, pages 22 to (1949) Helbergerreacted aqueous sodium hydroxide treated cellulose with butane sultoneto form a water soluble adduct.

The specification of the present invention teaches the use of anon-aqueous technique for obtaining a higher sulfur add-on. Thepreferred solvent utilized in the process of this invention is tertiarybutanol. However, there are other solvents which could be selected forobtaining an acceptable sultone-cellulose. The investigation leading tothis invention yielded data which indicates that an amount of sulfur inexcess of that added by use of water at C in 20 hours of reaction can beadded in a single hour by the process of this invention. The presentinvention further teaches that a temperature as low as 35C correlatedwith reaction time of 1 hour will add as much sulfur to the cellulosicsultone product as the highest quantity addedby the aqueous process ofUS. Pat. No. 3,506,390 under the most extreme of conditions, that is,longer times, higher temperatures-and higher concentration of sultone.

According to the process of the present invention, dry preswollen cottonis converted to sodium cellulosate by reacting the swollen cotton withsodium methoxide. This, of course, is knownby those skilled in the artof textile processing. The sodium cellulosate thus produced is thenwashed with tertiary butanol. The sodium cellulosate at this point mustbe either stored under nitrogen in the solvent, which in this casehappens to be tertiary butanol, or reacted immediately with a sultone intertiary butanol. It should be emphasized that the use of tertiarybutanol is preferred because the use of methanol, water, or otherprimary alcohol will reverse the formation of sodium cellulose, loweringthe sodium content.

No sodium hydroxide nor sodium alkoxide is employed in the sultonesolution of the present process; therefore the sultone solution can beused repeatedly and the reaction products contain more sulfur than theproducts of the prior art (an aqueous procedure). The products of thepresent invention are similar to those of the prior art and can be usedfor the same purposes except that the products of the invention have amuch higher content (as high as about 10%) when compared to thoseof theprior art. Among these the use of the sulfonic acid group in subsequentreaction, as an acidic catalyst in crosslinking or polymerizationreactions, and as an ion exchange medium can be considered significant.

Although sodium methoxide is preferred in the preparation of the alkalicellulosate, variations can be employed, such as the use of potassiummethoxide or other alkali earth methoxide with any primary alcohol.

fibers, yarns, fabrics, or other materials which contain cotton, rayon,wood, linen, and the like.

Although the example reactions were carried out by immersion of thecellulosic material in cylinders containing the reagents, other means ofcontacting the textiles can be used-These include, but are not limitedto,

padding, dipping, and spraying.-

' The sultone used for illustration is propane sultone,

but butane sultone could be used and other sultones as well can besimilarly employed.

The time, temperature, and concentration of sultone in tertiary butanolcan vary over'a wide range, depending on the desired result. Thetemperature can vary from about 26 to about 82C, i.e., over thetempera-- ture range in which tertiary butanol is liquid. The time canvary from minutes to hours, depending on the.

amount of reaction desired and the temperature used, although sufficientreaction can usually be accomplished in a period of from fifteen minutesto one hour.

The concentration of sultone in tertiary butanol can .vary from 1 to25%, although'l0% was found to produce good results and there seemed noadvantage to higher concentrations.

In a typical laboratory'use of this process a swatch of 3.12 oz. persquare yard X 80 count) cotton printcloth which had been preswollen indimethylformamide, dried and then reacted with sodium methoxide toproduce the sodium cellulosate, was washed with tertiary butanol andthen immersed in a 10% solution of propane sultone in tertiary butanoland kept there for a period of 1 hour at 50C. At the end of the reactionperiod the fabric sample was removed from the sultone solution, squeezedto remove excess solution and then washed in a water bath. The resultantproduct had a 2.85% sulfur. Although this sample of sodium cellulosatehad 1.25 meq. of sodium per gram of material, sodium cellulosate hasbeen prepared in this manner with up to 4.0 meq. of sodium per gram ofmaterial. This means that use of this process can result in productswith sulfur contents of up to sulfur.

The examples belows are provided to illustrate the invention and are notto be construed as limiting the invention in any manner whatever.

EXAMPLE 1 Illustrating the advantage of usingtertiary butanol both as awashing'agent for the freshly formed sodium cellulosate and in thesubsequent reaction A 12 in. square swatch for 80 X 80 count cottonprintcloth weighing 3.12 oz'./yd was soaked overnight indimethylformamide to preswell it and dried, then immersed in sodiumalkoxide to produce sodium cellulosate. It was then washed three timeswith tertiary butanol to remove excess sodium ions. The sodiumcellulosate fabric which contained 1.25 meq. Na per gram, while stillwet with tertiary butanol, was placed in a cylinder containing 250 ml.of a 10% solution of propane sultone in tertiary butanol. The cylinderand contents were kept at 50C for a period of 1 hour. At the end of onehour reaction the fabric was removed from the propane sultone solution,excess solution squeezed out and ple added no sulfur. V

Conclusion: Tertiary butanol is necessary as a washing agent after thesodium cellulosate is formed and subsequent reaction in a solution ofthe sultone in this solvent adds sulfur whereas sulfur is notadded whenmethanol or water are used.

EXAMPLE 2 Illustrating that other 'nonaqueous solvents can be employedwith propane sultone however unsatisfactory Example 1 was repeated butemploying other solvents in the reaction of the sodium cellulosate withpropane sultone. The results are here presented as percent sulfurcontent in the final product:

tertiary butanol 2.97% dimcthylt'ormamidc 1.86% acetone 2.15% water0.9l%

EXAMPLE 3 Illustrating limit of reaction with respect to the addition ofbase in the'propane sultone solution Example I was repeated except that2% sodium hydroxide was added to the solution of propane sultone intertiary butanol. The sulfur analysis obtained for the product was2.20%.

EXAMPLE 4 Illustrating reaction time limit Example 1 was repeated in aseries of experiments to point out the relatively small changes obtainedand the three experiments, the same propane sultone solution 5 limitobserved as the reaction time was varied from 1 hour to 24 hours. Theresults are indicated in terms of sulfur content of the final product.

Reaction Time thrs.) l 3 6 16 24 Sulfur 2.83 2.90 2.92 2.96 2.95

EXAMPLE 5 Varying temperature Example 1 was repeated in a series ofexperiments to point out changes obtained and the limit observed as Itemperature was varied from 25 to C. The results are indicated in termsof sulfur content of the final product.

Reaction Temp.(C) 25 p 35 50 6O 75 Sulfur 1.80 2.20 2.90 3.10 3.08

EXAMPLE 6 Reusing the propane sultone solution Example 1 was repeatedexcept that, in a series of in tertiary butanol was employed, that is,the reactants for Sample 2 had already been used in reacting Sample 1,and were subsequently used inreacting Sample 3. The results areindicated in terms of sulfur content of the final product.

Sample 1 Sample 2 Sample 3 V Sulfur 2.91 2.94 2.88

Conclusion: The propane sultone, and possibly other sultones, intertiary butanol may be used over and over again with substantially'thesame-results as those of the initial reaction. it is to be expected thatmakeup solution will have to be added during normal repeated use but nomakeup, however, was employed in the preparation of Sample 2 and 3.

EXAMPLE 7 Illustrating concentration limit Example 1 was repeated in aseries of 3 experiments where the concentrations were varied from 5% to20%.. The results are indicated in terms of sulfur concentration.

Sultonc Concentration Sulfur 1.61 2.78 2.84

We claim:

1. A process for producing sultone celluloses having ion-exchangeproperties with acid character, the process comprising reacting, in anon-aqueous solvent, washed alkaliearth cellulosate with sultone so asto yield a fibrous sultone cellulose.

2. The process of claim 1 wherein the alkali earth cellulosate is sodiumcellulosate.

3. The process of claim 1 wherein the cellulosate is' obtained byreacting a cellulosic material with sodium methoxide in non-aqueoussolvent.

4. The process of claim 3 wherein the cellulosic material is swollenwith dimethylformamide before reacting with the sodium methoxide.

5. The process of claim 1 wherein the sultone is a hydrocarbon sultoneat a concentration of from 5 to 25% in the non-aqueous solvent.

6. The process of claim 1 wherein the solvent is tertiary butanol.

7. The process of claim 5 wherein the hydrocarbon sultone is propanesultone.

8. The process of claim 5 wherein the hydrocarbon sultone is butanesultone.

9. The. product produced by the process of claim wherein the sulfurcontent is as high as about 10% with respect to the weight of thesultone-cellulose.

10. The product produced by the process of claim 1 wherein the sulfurcontent is about 10% with respect to the weight of thesultone-cellulose.

1. A PROCESS FOR PRODUCING SULTONE CELLULOSES HAVING IONEXCHANGEPROPERTIES WITH ACID CHARACTER, THE PROCESS COMPRISING REACTING, IN ANON-AQUEOUS SOLVENT, WASHED ALKALI EARTH CELLULOSE WITH SULTONE SO AS TOYIELD A FIBROUS SULTONE CELLULOSE.
 2. The process of claim 1 wherein thealkali earth cellulosate is sodium cellulosate.
 3. The process of claim1 wherein the cellulosate is obtained by reacting a cellulosic materialwith sodium methoxide in non-aqueous solvent.
 4. The process of claim 3wherein the cellulosic material is swollen with dimethylformamide beforereacting with the sodium methoxide.
 5. The process of claim 1 whereinthe sultone is a hydrocarbon sultone at a concentration of from 5 to 25%in the non-aqueous solvent.
 6. The process of claim 1 wherein thesolvent is tertiary butanol.
 7. The process of claim 5 wherein thehydrocarbon sultone is propane sultone.
 8. The process of claim 5wherein the hydrocarbon sultone is butane sultone.
 9. The productproduced by the process of claim 1 wherein the sulfur content is as highas about 10% with respect to the weight of the sultone-cellulose. 10.The product produced by the process of claim 1 wherein the sulfurcontent is about 10% with respect to the weight of thesultone-cellulose.